Despite an initial focus on negative threatening stimuli, researchers have more recently expanded the investigation of attentional biases toward positive rewarding stimuli. The present meta-analysis systematically compared attentional bias for positive compared with neutral visual stimuli across 243 studies (N ϭ 9,120 healthy participants) that used different types of attentional paradigms and positive stimuli. Factors were tested that, as postulated by several attentional models derived from theories of emotion, might modulate this bias. Overall, results showed a significant, albeit modest (Hedges' g ϭ .258), attentional bias for positive as compared with neutral stimuli. Moderator analyses revealed that the magnitude of this attentional bias varied as a function of arousal and that this bias was significantly larger when the emotional stimulus was relevant to specific concerns (e.g., hunger) of the participants compared with other positive stimuli that were less relevant to the participants' concerns. Moreover, the moderator analyses showed that attentional bias for positive stimuli was larger in paradigms that measure early, rather than late, attentional processing, suggesting that attentional bias for positive stimuli occurs rapidly and involuntarily. Implications for theories of emotion and attention are discussed.Keywords: attentional bias, positive emotion, reward, emotional theories, attention Emotions guide behavior (e.g., approach or avoidance), modulate many cognitive processes (e.g., memory and decision making), and signal the presence of important events in the environment . When several stimuli compete for access to the limited attentional resources of an individual, a bias toward emotional stimuli allows efficient detection of these events and rapid preparation of adaptive reactions (Pourtois, Schettino, & Vuilleumier, 2013). Attentional bias for emotional stimuli has attracted considerable interest in neuroscience (Vuilleumier, 2005) and psychology (Van Bockstaele et al., 2014;Yiend, 2010). Initially, experimental research in both fields mainly focused on the negative emotion of fear. Indeed, fear was one of the first emotions investigated in an experimental setting in neuroscience through fear conditioning in rodents (see LeDoux, 1996). The earliest investigations in human research tried to extend these findings with the use of fear-relevant stimuli such as faces expressing fear or anger (Mogg & Bradley, 1998;Vuilleumier, Armony, Driver, & Dolan, 2001). In addition, a large corpus of studies investigated attentional bias for threatening stimuli in healthy participants, as well as in participants experiencing a variety of anxiety disorders (for an encompassing meta-analysis on anxious and nonanxious participants, see Bar-Haim, Lamy, Pergamin, Bakermans-Kranenburg, & van IJzendoorn, 2007).Despite this initial focus on threatening stimuli, researchers have more recently expanded the investigation of attentional biases to rewarding stimuli. In the last decade, the topic of attentional bias for these...

a b s t r a c tAnimal research has shown it is possible to want a reward that is not liked once obtained. Although these findings have elicited interest, human experiments have produced contradictory results, raising doubts about the existence of separate wanting and liking influences in human reward processing. This discrepancy could be due to inconsistences in the operationalization of these concepts. We systematically reviewed the methodologies used to assess human wanting and/or liking and found that most studies operationalized these concepts in congruency with the animal literature. Nonetheless, numerous studies operationalized wanting in similar ways to those that operationalized liking. These contradictions might be driven by a major source of confound: expected pleasantness. Expected pleasantness underlies cognitive desires and does not correspond to animal liking, a hedonic experience, or to animal wanting, which relies on affective relevance, consisting of the perception of a cue associated with a relevant reward for the organism's current physiological state. Extending the concept of affective relevance and differentiating it from expected pleasantness might improve measures of human wanting and liking.

a b s t r a c tSome stimuli can orient attentional resources and access awareness even if they appear outside the focus of voluntary attention. Stimuli with low-level perceptual salience and stimuli with an emotional content can modulate attention independently of voluntary processes. In Experiment 1, we used a spatial cuing task to investigate whether stimuli that are controlled for their perceptual salience can modulate the rapid orienting of attention based exclusively on their affective relevance. Affective relevance was manipulated through a Pavlovian conditioning paradigm in which an arbitrary and affectively neutral perceptual stimulus was associated with a primary reward (i.e., a chocolate odor). Results revealed that, after conditioning, attentional resources were rapidly oriented toward the stimulus that was previously associated with the reward. In Experiment 2, we used the very same conditioning procedure, but we devaluated the reward after conditioning for half of the participants through a sensory-specific satiation procedure. Strikingly, when the reward was devaluated, attention was no longer oriented toward reward-associated stimuli. Our findings therefore suggest that reward associations rapidly modulate visual processing independently of both voluntary processing and the perceptual salience of the stimulus. This supports the notion that stimuli associated with primary rewards modulate rapid attention orienting on the basis of the affective relevance of the stimulus.

Stress can increase reward pursuits: This has traditionally been seen as an attempt to relieve negative affect through the hedonic properties of a reward. However, reward pursuit is not always proportional to the pleasure experienced, because reward processing involves distinct components, including the motivation to obtain a reward (i.e., wanting) and the hedonic pleasure during the reward consumption (i.e., liking). Research conducted on rodents demonstrates that stress might directly amplify the cue-triggered wanting, suggesting that under stress wanting can be independent from liking. Here, we aimed to test whether a similar mechanism exists in humans. We used analog of a Pavlovian-Instrumental Transfer test (PIT) with an olfactory reward to measure the cue triggered wanting for a reward but also the sensory hedonic liking felt during the consumption of the same reward. The analog of a PIT procedure, in which participants learned to associate a neutral image and an instrumental action with a chocolate odor, was combined with either a stress-inducing or stress-free behavioral procedure. Results showed that compared with participants in the stress-free condition, those in the stress condition mobilized more effort in instrumental action when the reward-associated cue was displayed, even though they did not report the reward as being more pleasurable. These findings suggest that, in humans, stress selectively increases cue-triggered wanting, independently of the hedonic properties of the reward. Such a mechanism supports the novel explanation proposed by animal research as to why stress often produces cue-triggered bursts of binge eating, relapses in drug addiction, or gambling. Keywords: stress, incentive salience, wanting, liking, human Pavlovian-Instrumental TransferSupplemental materials: http://dx.doi.org/10.1037/xan0000052.supp Have you ever eaten more high-calorie foods during a stressful period? As documented by a consistent corpus of literature (e.g., O'Connor & Conner, 2011), stress cannot only increase the consumption of high-calorie foods, but it can also increase the use of other kinds of rewards, such as drugs (Sinha, 2001) or sexual stimuli (Chumbley et al., 2014). Although these effects of stress have been proven to have a large impact on public health problems (e.g., addiction relapses or binge eating; Lo Sauro, Ravaldi, Cabras, Faravelli, & Ricca, 2008), the underlying psychological mechanisms remain poorly understood.It has been proposed that rewards are used to reduce the negative effects of stress, which are compensated by the hedonic pleasure triggered by their consumption (Koob & Le Moal, 2001). According to this proposal, stress increases the pursuit of rewards, as consumption is made even more pleasurable by relieving the negative effects of stress.The incentive salience theory proposes an alternative mechanism in which the key principle is independent of the hedonic properties of the reward (Berridge & Robinson, 1998). According to this theory, the pursuit of a reward is not always dir...

Using a word association paradigm we examined the extent to which readers can overcome the specific interpretation of the grammatical masculine form in French when instructed to embrace its generic meaning. In two experiments participants were to decide whether a person introduced by a kinship term (e.g. aunt) could be part of a group represented by a role name (e.g. musicians). After the completion of the first half of the experiment, participants were explicitly reminded about the generic interpretation and use of the masculine form. Although the reminder resulted in some level of generic interpretation, there were still strong traces of the specific interpretation in the response times, regardless of participants' inhibition capacities (Experiment 1). Adding a supplementary constraint by exposing readers to distractor role names in feminine forms (Experiment 2) did not reveal any different effects.The results indicated that although readers can be motivated to elaboratively activate the generic interpretation of the masculine form, the latter can not completely overrule a more passively activated specific one. <164 words>

There is a dichotomy in instrumental conditioning between goal-directed actions and habits that are distinguishable on the basis of their relative sensitivity to changes in outcome value. It is less clear whether a similar distinction applies in Pavlovian conditioning, where responses have been found to be predominantly outcome sensitive. To test for both devaluation insensitive and devaluation sensitive Pavlovian conditioning in humans, we conducted four experiments combining Pavlovian conditioning and outcome devaluation procedures while measuring multiple conditioned responses. Our results suggest that Pavlovian conditioning involves two distinct types of learning: one that learns the current value of the outcome which is sensitive to devaluation, and one that learns about the spatial localisation of the outcome which is insensitive to devaluation. Our findings have implications for the mechanistic understanding of Pavlovian conditioning and provide a more nuanced understanding of Pavlovian mechanisms that might contribute to a number of psychiatric disorders.

It has been suggested that there are two distinct and parallel mechanisms for controlling instrumental behavior in mammals: goal-directed actions and habits. To gain an understanding of how these two systems interact to control behavior, it is essential to characterize the mechanisms by which the balance between these systems is influenced by experience. Studies in rodents have shown that the amount of training governs the relative expression of these two systems: Behavior is goal-directed following moderate training, but the more extensively an instrumental action is trained, the more it becomes habitual. It is less clear whether humans exhibit similar training effects on the expression of goal-directed and habitual behavior, as human studies have reported contradictory findings. To tackle these contradictory findings, we formed a consortium, where four laboratories undertook a preregistered experimental induction of habits by manipulating the amount of training. There was no statistical evidence for a main effect of the amount of training on the formation and expression of habits. However, exploratory analyses suggest a moderating effect of the affective component of stress on the impact of training over habit expression. Participants who were lower in affective stress appeared to be initially goal-directed, but became habitual with increased training, whereas participants who were high in affective stress were already habitual even after moderate training, thereby manifesting insensitivity to overtraining effects. Our findings highlight the importance of the role of moderating variables such as individual differences in stress and anxiety when studying the experimental induction of habits in humans.

It has long been posited that among emotional stimuli, only negative threatening information modulates early shifts of attention. However, in the last few decades there has been an increase in research showing that attention is also involuntarily oriented toward positive rewarding stimuli such as babies, food, and erotic information. Because reproduction-related stimuli have some of the largest effects among positive stimuli on emotional attention, the present work reviews recent literature and proposes that the cognitive and cerebral